Hide Z-seam as well as possible?

[omexlu 0]

Hello,

 

How can I hide as best as possible the Z seam in Cura?

 

I have tried different things like:

- Sharpest edge
- etc.

 

Unfortunately, this does not bring the desired result.

With angular objects this works quite well because I can put the Z-seam on the sharpest edge.

 

However, if I now print a figure with many curves, I have these ugly Z-seams everywhere.

 

What is the best way to place this?

 

So far I've sanded them away but even that doesn't look very nice.

 

Thanks in advance.

[GregValiant 1,245]

There is going to be a Z seam.  It's the nature of the FDM process.  Playing with "outer wall wipe distance" and "outer before inner walls" can have an effect but in the end - there is going to be a Z seam.

If you are printing a cylinder or a ball, there are no corners to hide it in.  The two options become: "random" which will leave little blobs everywhere (but they won't be lined up) and "none" which will line up the blobs and results in the Z seam line you are talking about.  The "line" is easier to remove (sanding) and the random blobs are less noticeable unless you look close.  I usually go with "none".

@kmanstudios or @geert will know better ways to mitigate the Z seam.

[kmanstudios 1,120]

I do not really mess with z-seam settings since most of my stuff is organic in nature. I also mainly use TPLA these days and it x-acto's very cleanly. So, I may be just slicing off the tell tale signs with the blade.

[GregValiant 1,245]

A knife slice is very clean.  Is there a way to smooth out the scratches from sandpaper?  Even a fine grit will leave tool marks.  I've heard of acetone smoothing for ABS.  Is there something for PLA?

 

Story time.

I was working on a failure in some large plastic chemical tanks.  The 35mm thick walls of the tanks had been edge welded and one of the things that was being looked at was weld penetration.  After slicing the pieces through the weld, it was necessary to polish the welds to check penetration.  They couldn't be buffed as no heat could be tolerated.  After some thought I polished a good ole' carpenters plane with a diamond knife sharpener and planed the weld area.  The finish was like a mirror (which is where I was going with this) and proved that the welds penetrated by 8mm into both pieces.

So yes, a knife edge is good.  It's a pity really that I was never allowed to play with sharp objects.  I could have been a brain surgeon.

Edited June 12, 2021 by GregValiant

[geert_2 557]

I do use surgical blades (scalpels) to remove blobs and strings, so I am a plastic surgeon.  :-)

 

You can chemically smooth PLA and PET with dichloromethane. This works like acetone on ABS. First remove all big defects with a knife and with filing/sanding, and then chemically smooth. One light application is best, a quick brush-on. If you overdo it, it will penetrate too deep into the plastic, and make it weak, deform and crack after a longer time. It's a solvent, so it dissolves stuff and then dries out...

 

It smooths into a high-gloss, which feels very smooth, but this also highlights any waves or bigger irregularities like ringing.

 

Smoothing is highly required for 3D-printed moulds: you can remove the cast much easier than in an unsmoothed mould.

 

Search for my post "Chemical smoothing PLA and PET with dichloromethane" (or something similar), with more explanation and photos.

 

One part as-printed, the other smoothed:

 

 

 

[kmanstudios 1,120]

53 minutes ago, geert_2 said:

so I am a plastic surgeon.  🙂

😂😂😂

[GregValiant 1,245]

Don't encourage him Kman...the puns will just get worse.

[kmanstudios 1,120]

2 hours ago, GregValiant said:

Don't encourage him Kman...the puns will just get worse.

Lawsy, I hope so! A good grin in the AM is a good thing. And all puns are allowed as they are 2/3 P-U 😛